Manganese (Mn), is an element, utilized as a micronutrient in plant nutrition. 

It is needed in trace amounts in early vegetation phase for successful germination and/or propagation.

Mn deficiencies are quite difficult to diagnose and usually only happen via lock out as most complete fertilizers have sufficient amounts of this element so toxicity is quite rare, but when this happens most actually confuse the issue as an Iron deficiency, and funny enough the other way around too.

The problem is displayed by the plants as venial chlorosis, where yellowing occurs around the center of the vein (which remains green), and in some plant species can show black/grey mottled spots around the edges of the leaflets and as it progresses it consumes the leaf from the edges inward.

Manganese is an immobile element, which means the plant cannot translocate to correct the problem.  

Flushing with a pH of 5.6-5.8 is the immediate corrective procedure, once the excess (buildup of salts) has been flushed away, we need to adjust the new solution that goes back into the reservoir or coco system/pot. So, by adjusting the new solution with a lower base nutrient dose the plant can focus on utilizing a solution that is within range and correct the deficiency. This can only be fixed by added to root zone, foliar treatments do not work because of Mn’s positivity (Mn+3 Mn+2)

Manganese is also used in many maturation formulas; these products help plants round off and finish much quicker, usually because of the remaining presence of nutrition, if elements are flushed properly then maturation formulas in our opinion are not needed, just a good water source and a corrected pH.

  • Plays a crucial part in Chlorophyll formation & photosynthesis.
  • Synergizes the use of, N, Ca and P in the growth and maturation phase.
  • Mn deficiencies occur usually when the substrate pH has risen
  • Antagonizes plants ability to use Iron & vice versa


Manganese problems are a direct impact of over feeding as the Fe/Mn changes, the greater the iron content, then availability of Mn is limited



> Propagation
> Hydroponic Equipment
> Pest & Disease
> Hydroponic Environment
> Harvest
> How To...
> Geek Out With A-Grade
> Water Control
> Plant Training
> Grow Medium
> Troubleshooting
> Hydroponic Basics

Other Tutorials

5 Best Hydroponic Nutrients for Premium Yields & Growth
Optimising Root Growth - Geopot Fabric Pots and Air Pruning
Hydroponics - Boron Deficiency
Hydroponics - How to feed your plants
The Three Best Hydroponic Nutrients for Quality & Yield

premium hydroponic store

We're committed to helping communities in Australia grow
Shop now